if you are thinking of buying a new phone, and you have anything older than an iPhone 6, you should buy an iPhone 6S Plus. It is the best iPhone ever made, and it is right now the best phone on the market. If you're upgrading from an iPhone 5S or anything older, it will blow your mind. There just aren't other companies that can roll out a feature like 3D Touch and make it work in a way that suggests the creation of entirely new interface paradigms, and every other phone maker needs to figure out exactly why Apple's cameras are so consistent before they can really compete.

Note that I said the 6S Plus, not the 6S. I am convinced that in another year or so every phone will be the size of the 6S Plus, so if you're going to jump in, just go all the way. You'll get a slightly better camera and a little more battery life out of the deal as well. The future is here. You should face it with a gigantic screen.

Moving between apps is lightning fast. Fast-moving games are as smooth as Billy Dee Williams on a silk surfboard. The Touch ID sensor is instantaneous: By the time you've pressed the home button to wake up the phone, you've already authenticated yourself and are on the home screen. The new iPhones can get on faster Wi-Fi and, where available, 4G networks. These otherwise-unglamorous performance boosts don't get the crowd on their feet at product launches, but they're exactly what a great smartphone needs to achieve its ultimate goal, which is to get out of your way. With prodigious speed, well-thought-out interfaces, and flawless hardware-software integration, these new iPhones provide the tool for whatever it is you're doing and just let you do it. The best thing about the 6S and 6S Plus isn't all the new stuff to pay attention to, it's all the stuff you never notice.

I have a theory, just between you and me, that the new iPhones we'll be seeing from Apple are never going to go back to the ‘tick/tock' cycle. Competition is too fierce, the scope of Apple's other ambitions is ever increasing, and with chip design in-house and clearly firing on all cylinders, the company has the resources and tools to introduce the most rapid refinements to the iPhone than ever before. We'll see if that's true next year. But for now, both the iPhone 6s and iPhone 6s Plus are worth your attention and, if it's in your budget, a purchase. The camera alone is worth the price of admission - it's truly great - the glimpse into the future of three dimensional computing is just a bonus.

From design to construction to software to camera, the iPhone 6S Plus is a high-quality device. It has ample power to run everything from endless Safari tabs to video and intense 3D games. A 6.23-inch-tall device may be on the large side for some people, but for those who prize a larger display and prosumer-level photographic and video power, they can't go wrong with the iPhone 6S Plus. Is it a must-have upgrade? No, unless you must have gorgeous 4K video and can't live without the innovative 3D Touch. By sheer volume, iOS 9 probably adds more feature enhancements than the iPhone 6S Plus, and you can get it for free. This doesn't diminish Apple's accomplishment. Take me, for instance: Now that I've had a taste of 4K and Peek and Pop, I don't know if I can go back

If you have an iPhone 6, you won't be overly jealous of those who get a 6s-maybe just a tad envious of those Live Photos. If your iPhone is more than two years old, this is the phone to get. Just make sure to pay Apple's ransom for the 64GB version. The story of the iPhone 6s is the same as the 5s, or the 4s before it. It is a slightly better iPhone-that must be what the S stands for. And like its "S" predecessors, it doesn't address all complaints. That's what the iPhone 7 is for-right, Apple?

An iPhone S update year usually means a couple of new features that most people could take or leave, but the iPhone 6S is the most exciting S model for a long time. It bucks the usual trend, delivering a phone that will offer plenty to iPhone users new and old alike, with 3D Touch a principle new feature that will lead iPhone functionality going forward.

Apple's ‘s' generation iPhones have gained a bad reputation in recent years for failing to excite on the level the more comprehensive 4, 5 and 6 years have. But Apple has clearly attempted to redress the constant accusations of a failure to innovate with 3D Touch and Live Photos, two not wholly original concepts, but ones which work exceptionally well. But as ever with Apple, none of this comes cheaply. You'll have to fork out £539 to buy the 16GB model outright, £619 for 64GB and £699 for 128GB, eye-watering prices for what is an excellent, but nonetheless still far from the most highly-specced phone on the market. It's also significantly lighter than the 6s Plus, and - for those who care - you can slip it into your pocket with ease. I personally prefer a larger display, which is why I've given the 6 Plus the higher star rating, but this is purely a matter of preference.

If you can justify the price, are fully committed to the iOS / OS X ecosystems and prefer the smaller end of the phablet spectrum, the iPhone 6s could well be the one for you. It's unlikely to win over many Android fandroids who will continue to decry what they deem as Apple's arrogant appropriation of their years-old features, but when an iPhone's this good, the rest is noise.

"" is the slogan of Apple's marketing campaign for the iPhones 6S. I can't beat that. I've been testing both models for 12 days, and what Apple is saying about the new iPhones is true. They don't look new, but almost everything about them is new.

These new features are great, all of them. But realistically, they're not enough for me to justify an off-year iPhone upgrade, which I'm told by certain parties who shall remain nameless is "a reckless purchase - possibly stupid."

But 3D Touch, the most significant of the iPhone 6s's tentpole features, is. Easily. Built on a system of sensors that detect touch pressure across the face of the iPhone 6s's display, 3D Touch triggers pop-up menus and previews based on how firmly you press down. Currently, it supports two interactions "peek" and "pop," with peek calling up a preview of an app or message, or a brief contextual menu, and pop launching the app itself. Each interaction is accompanied by a different tiny vibration that helps you distinguish between them. It is surprisingly useful - particularly for power users who do a lot of work from their iPhones. I'm already using it constantly, and I am impressed with how good it is at interpreting the force of my touch. It's very much an Apple innovation - a seemingly subtle change so thoughtfully executed that it proves transformative.

Now that smartphones can do more than a million different things with apps, you have to wonder whether it matters when Apple adds two main new features to its latest iPhones.

The answer, to cut to the chase, is yes. That's because when Apple incorporates new smartphone capabilities, the features may become widely used by consumers and then copied by competitors.